Parasitic barnacle Heterosaccus californicus
Sheep crab Loxorhynchus grandis
Welcome to a freakish world where parasites compel their hosts to do their
bidding. A male sheep crab infected by a parasitic barnacle is literally femi-
nized. It stops developing fighting claws, and its abdomen widens, providing
a “womb” for the barnacle to fill with its brood pouch. Nurtured by the crab,
the eggs hatch. Thousands of baby barnacles disperse to infect anew.
ECOLOGICAL PARASITOLOGY GROUP, UNIVERSITY OF CALIFORNIA, SANTA BARBARA
MEETNATURE’SNIGHTMAREMINDSUCKERS